变氧浓度环境下煤自燃特性实验研究

发布时间：2018-08-16 18:21

【摘要】：目前国内外对煤自燃氧化产物的生成规律研究大都是在O2浓度为21%的条件下，而对不同O2浓度条件下氧化产物的生成规律研究较少。在煤矿井下采空区自燃带、封闭火区等自燃危险区域内，O2浓度通常低于正常大气中的21%，而自燃火灾的发生往往是由该区域引起的。本文研究了在21%、17%、13%、9%、5%和3%氧浓度环境下分别进行程序升温实验，分析出清水营矿煤样在20℃~220℃温度范围内自燃产物浓度变化情况，确定CO为检测自然发火的标志气体，同时以CH4、C2H4、C2H6和CO/CO2作为预警指标。并发现煤样在不同氧浓度下的临界温度点主要集中在60～80℃之间，可见氧气浓度对同一煤样的临界温度点没有明显影响，氧浓度虽然在一定程度上改变了煤氧复合反应速率，，但是并不能改变其速率明显提高的起始温度。通过对不同氧浓度环境下煤样特定温度耗氧速率进行分析，得出同一氧浓度下，耗氧速率随温度的升高而增大，前期耗氧速率低、增长慢，后期耗氧速率高增长快；氧浓度的不同会影响耗氧速率大小，同一温度下氧浓度高则耗氧速率大，但耗氧速率随温度的变化趋势不随氧浓度的变化发生改变。通过研究煤自燃程度的特征温度以及不同氧气浓度环境对煤自燃氧化产物的影响，分析计算出煤样耗氧速率、气体产生速率、放热强度等自燃特性参数，更准确掌握实验煤样的自燃特性；对不同氧气浓度下温度对自燃产物浓度及其比值的影响规律进行分析，为更加有效的制定自燃防治措施提供依据，对煤的自燃预报预测具有重大意义。
[Abstract]:At present, most of the research on the generation law of coal spontaneous combustion oxidation products at home and abroad is under the condition of O2 concentration of 21%, but less on the generation law of oxidation products under the condition of different O2 concentration. The occurrence is often caused by the area.
In this paper, temperature programmed experiments were carried out in 21%, 17%, 13%, 9%, 5% and 3% oxygen concentration environments respectively. The concentration changes of spontaneous combustion products in Qingshuiying Coal Mine were analyzed in the temperature range of 20 ~220 ~C. CO was determined as a marker gas for detecting spontaneous combustion, and CH4, C2H4, C2H6 and CO/CO2 were used as early warning indicators. The critical temperature point under the concentration is mainly between 60 and 80 C. It can be seen that the oxygen concentration has no obvious effect on the critical temperature point of the same coal sample. Although the oxygen concentration has changed the rate of the coal-oxygen complex reaction to a certain extent, it can not change the initial temperature of the rate increase obviously. The analysis of temperature oxygen consumption rate shows that oxygen consumption rate increases with the increase of temperature under the same oxygen concentration, the former is low, the latter is slow, and the latter is high; the different oxygen concentration will affect the oxygen consumption rate, and the higher the oxygen concentration, the higher the oxygen consumption rate, but the oxygen consumption rate does not change with the temperature. The change of oxygen concentration changed.
Through studying the characteristic temperature of coal spontaneous combustion degree and the influence of different oxygen concentration environment on coal spontaneous combustion and oxidation products, the oxygen consumption rate, gas production rate, heat release intensity and other spontaneous combustion characteristic parameters of coal samples were analyzed and calculated, so as to grasp the spontaneous combustion characteristics of experimental coal samples more accurately. The analysis of the influence law of the value provides a basis for more effective formulation of spontaneous combustion prevention measures, and has great significance for the prediction of coal spontaneous combustion.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TD752.2

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